regarding the segate pocket drive....
For $100 you can make your own 40gb usb drive..... 40gb laptop drive and usb enclosure.... MUCH faster, MUCH larger capacity, and not a whole lot bigger.....
check out newegg.com for example...they already have units built, or make your own....40GB 2.5" drive + USB 2.0 2.5" enclosure (use those keywords)
My $.02
Edit: one example...abeti $124
LINK
Or build yer own....
$76
HD
+
$14
Enclosure
+shipping
--------
$100 for a 5400rpm 40gb portable drive...easy...
And if size is important, check out the PQI 1GB usb drives...they rule...
LINK $69